JPH09217798A - Closed wave motion gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized, compact and structurally simple closed wave motion gear device suitable for use as a reduction gear of a driving mechanism sued in a clean room. SOLUTION: A wave motion gear device 1 is provided with a device housing 2, first and second end plates 3, 4 arranged on both end openings, a hollow input shaft 5, and a sealing space 13 sectioned and formed by first to fourth sealing means 8, 9, 11, 12 for sealing these members, and a flat wave motion gear mechanism 20 is incorporated inside it. The wave motion gear mechanism 20 is constituted of a rigid internal gear 310, a silk hat-shaped flexible external gear 220 inside it, and a wave generator 230 mounted inside it. Lube oil of the wave motion gear mechanism is completely prevented from leaking to the outside. The rust preventing treatment is applied on the device housing 2 exposed to the outside, the first and second end plates 3, 4 and both ends of the input shaft 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave gear device, and more particularly to a hermetic wave gear device suitable for use as a drive mechanism in a clean room or the like.

[0002]

2. Description of the Related Art As a wave gear device, a flexible external gear, which is a component of the wave gear device, is of an annular type, a cup type, or a top hat type. Has been. Among these, the applicant of the present invention has previously disclosed Japanese Patent Application Nos. 6-310834 and 6-3108.
No. 35 proposes a wave gear device including a flat top hat-shaped flexible external gear. If this flat top hat-shaped flexible external gear is used, the wave gear device can be made flat.

[0003]

The applicant of the present invention has a structure suitable for the case where the above-mentioned flat top hat-shaped flexible external gear is adopted in the specification of Japanese Patent Application No. 7-1209570. We propose a flat wave gear device.

An object of the present invention is to utilize this flat type wave gear device to realize a hermetic type wave gear device suitable for being incorporated into a drive mechanism used in a clean room or the like with a simple structure. .

[0005]

In order to solve the above-mentioned problems, in a hermetically-sealed wave gear device of the present invention, a cylindrical device housing and a first opening end on one side of the device housing are provided. A first end plate located on the other side of the device housing and a second end located on the other side of the device housing.
End plate, an input shaft coaxially arranged inside the device housing, both ends of which are rotatably supported by the first and second end plates, the first open end and the first end. A first sealing means for sealing between the first end plate, a second sealing means for sealing between the second open end and the second end plate, and a space between the first end plate and the input shaft. It has a third sealing means for sealing and a fourth sealing means for sealing between the second end plate and the input shaft, and these device housing, the first and second end plates, and A space sealed by the first to fourth sealing means is formed, and a wave gear mechanism is incorporated in the space.

In the hermetically-sealed wave gear device of this structure, the wave gear mechanism is incorporated in the hermetically sealed space, so that the lubricant supplied thereto does not leak outside. Further, in the case of arranging in a clean room or the like, it is necessary to perform rust prevention treatment so that rust does not occur on the outer peripheral portion of the device. In the device of the present invention, since each component constituting the wave gear mechanism is incorporated in the closed space, it is not necessary to perform rust prevention treatment. Only the surfaces of the device housing, the first and second end plates, the input shaft, the fastening bolts, etc. forming the closed space, which are exposed to the outside of the device, may be rust-proofed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the preferred embodiment of the present invention,
The following structure may be adopted as the above-mentioned wave gear mechanism. That is, the cylindrical body portion, the external teeth formed on the outer peripheral surface of the opening end of the body portion on the side of the first end plate, the radial direction from the opening end of the body portion on the side of the second end plate. A flexible external gear of the hat hat type having an annular diaphragm continuous toward the outer side of the outer peripheral surface and a thick annular boss continuous to the outer peripheral edge of the diaphragm, A ring-shaped rigid internal gear having inner teeth formed on its peripheral surface capable of meshing with the outer teeth, and a cylindrical body formed inside the cylindrical body having the outer teeth. It is possible to employ a configuration including a wave generator that bends in the direction and partially meshes the outer teeth with the inner teeth and moves the meshing position in the circumferential direction.

In this case, the input shaft is fixed to the wave generator and attached in a state of penetrating the wave generator.

Next, the rigid internal gear and the flexible external gear are
A bearing for supporting the relative rotation in a freely rotatable state can be arranged on the outer periphery of the cylindrical body of the flexible external gear. In this case, the outer ring of the bearing is fixed to the device housing, the annular boss and the second end plate, and the inner ring is fixed to the rigid internal gear and the first end plate. You can

Here, a cross roller bearing can be used as the bearing. In this case,
Between the second end plate and the annular step surface formed on the inner peripheral surface of the apparatus housing, the annular boss of the flexible external gear and the outer ring of the cross roller belling are sandwiched between these four end plates. A configuration is adopted in which the members are fastened and the rigid internal gear is sandwiched between the annular end face of the inner ring of the cross roller bearing and the inner annular end face of the first end plate. it can.

On the other hand, since the first sealing means seals between the device housing and the first end plate which is relatively rotatable with respect to the device housing, a magnetic seal can be adopted. .

Next, if the input shaft is a hollow input shaft,
By utilizing this hollow portion, another member can be arranged and wiring such as electric wiring can also be performed, which has an advantage that the degree of freedom in the device layout and the like is increased.

[0013]

EXAMPLE An example of the present invention will be described below with reference to FIG.

The hermetically-sealed wave gear device 1 of the present embodiment is provided with a device housing 2 having a cylindrical shape having open ends 201 and 202 at both ends. Open end 2 on one side
The first end plate 3 is arranged at 01 (first opening end), and the second end plate 4 is arranged at the opening end 302 (second opening end) on the other side. Inside the device housing 2, a hollow input shaft 5 is arranged coaxially in the direction of the device axis 1a. The first end portion 501 of the hollow input shaft 5 is exposed from the through hole 301 formed in the first end plate 3, and the outer peripheral portion of the hollow input shaft 5 is exposed to the first end plate 3 via the ball bearing 6. It is rotatably supported. The other second end portion 502 of the hollow input shaft 5 penetrates through a through hole 401 formed in the second end plate and projects outward, and the outer peripheral portion of the second end portion 502 passes through the ball bearing 7 and the second end portion 502. End plate 4
Is rotatably supported.

Here, between the inner peripheral surface of the first end plate 3 and the outer peripheral surface of the first end portion 501 of the hollow input shaft 5, an oil seal (a first seal) mounted outside the ball bearing 6 is provided. Three
It is hermetically sealed by means 8). Similarly, the inner peripheral surface of the second end plate 4 and the second end 502 of the hollow input shaft 5 are
A space between the outer peripheral surfaces of is sealed by an oil seal (fourth sealing means) 9 mounted at a position outside the ball bearing 7. On the other hand, a magnetic seal (first sealing means) 11 is mounted between the outer peripheral surface 302 of the first end plate 3 and the inner peripheral surface of the open end 201 of the apparatus housing 2, and the space between them is provided. Is sealed. An O-ring (second sealing means) 12 is mounted between the outer peripheral surface 402 of the second end plate 4 and the inner peripheral surface of the open end 202 of the apparatus housing 2, thereby sealing between them. ing.

As described above, the device housing 1, the hollow input shaft 5, the left and right end plates 3 and 4, and the first to fourth sealing means (8, 9) holding the spaces therebetween in a sealed state. ,
A substantially annular closed space 13 is defined by (11, 12). A wave gear mechanism 20 having the following configuration is incorporated in the closed space 13.

The wave gear mechanism 20 includes an annular rigid internal gear 210, a top hat type flexible external gear 220, and
It is composed of a wave generator 230. Flexible external gear 22
Reference numeral 0 denotes a cylindrical body portion 221, external teeth 222 formed on the outer periphery of the opening end on one side thereof, and an annular diaphragm 2 continuous to the other opening end and extending at a right angle outward in the radial direction.
23 and a thick annular boss 224 which is continuous with the outer peripheral edge of the diaphragm 223. External teeth 22
A rigid internal gear 210 is arranged on the outer periphery of 2,
The inner teeth 211 and the outer teeth 222 formed on the inner peripheral surface thereof can mesh with each other. The wave generator 230 is fitted in the inner portion of the body portion 221 where the outer teeth 222 are formed.

The wave generator 23 comprises a rigid cam plate 231 having an elliptical contour and a bearing 232 fitted on the outer periphery thereof. In this example, the rigid cam plate 231 is integrally formed on the outer peripheral surface of the hollow input shaft 5. Of course, a separate rigid cam plate may be manufactured and fixed to the outer periphery of the input shaft 5. By the wave generator 230, the external teeth 222 of the flexible external gear 220 are bent in an elliptical shape, and mesh with the internal teeth 211 at both ends in the longitudinal direction. The wave generator 230 is also rotated by the rotation of the hollow input shaft 5, and the meshing positions of the outer teeth 222 and the inner teeth 211 are accordingly moved in the circumferential direction. Generally, the external teeth 222
Has two fewer teeth than the inner teeth 211,
When the meshing position moves in the circumferential direction, a relative rotation, which is significantly reduced as compared with the input rotation, is generated between the outer teeth and the inner teeth. This rotation can be taken out from the side of the internal or external teeth. Since such a deceleration principle is known, its detailed description is omitted in this specification.

Next, the body 221 of the flexible external gear 220 is formed.
A cross roller bearing 30 is arranged at a position between the second end plate 4 and the rigid internal gear 210 between the outer peripheral surface of the device and the inner peripheral surface of the device housing 1. The cross roller bearing 30 is composed of an outer ring 31, an inner ring 32, and rollers 33 arranged in an annular groove formed therebetween so as to be rollably and alternately intersected with each other.

In this example, the annular ring of the flexible external gear 220 is provided between the annular end face 311 of the outer ring 31 of the cross roller bearing 30 and the inner end face 403 of the second end plate 4 facing the annular end face 311. The boss 224 is arranged so as to be sandwiched from both sides. Further, the other annular end surface 312 of the outer ring 31
Is just in contact with the annular step surface 101 for receiving the outer ring formed on the inner peripheral surface of the apparatus housing 1. A large number of fastening bolt holes extending from the second end plate 4 side toward the device axis 1a are formed in these four members at predetermined angular intervals in the circumferential direction. Fastening bolts 40 are mounted in the bolt holes, and these four members are fastened.

From the side of the second end plate 4, a large number of mounting bolt holes 50 also extending in the direction of the apparatus axis 1a.
Is formed, and the side of the second end plate 4 and the device housing 2 can be attached and fixed to the side of the motor case or the like by utilizing these attachment bolt holes 50. Similarly, on the annular end surface of the second end portion 502 of the hollow input shaft 5, a large number of connecting bolt holes 60 extending in the direction of the device axis 1a.
The hollow input shaft 5 can be connected to a high speed rotating shaft (not shown) such as a motor output shaft by utilizing these connecting bolt holes 60.

On the other hand, the cross roller bearing 3
The rigid internal gear 210 is sandwiched from both sides between the annular end surface 321 of the inner ring 32 of 0 and the annular end surface 303 formed on the first end plate 3 facing the inner ring 32. Has been done. Then, these three members are formed with a large number of fastening bolt holes extending from the first end plate 3 side toward the device axis 1a, and by these attached fastening bolts 70, The three members are fastened.

It should be noted that a large number of mounting bolt holes 80, which also extend in the direction of the apparatus axis 1a, are formed from the first end plate 3 side. The end plate 3 side can be attached and fixed to the load side or the like.

The hermetically-sealed wave gear device 1 configured as described above
The second end plate 4 side is connected to a fixed side such as a motor case, and the other first end plate 3 side is connected and fixed to a load side member that is driven to decelerate and rotate. Also, the hollow input shaft 5
The second end 502 side of is connected to a motor output shaft or the like. When the hollow input shaft 5 rotates, a relative rotational motion is generated between the flexible external gear 220 and the rigid internal gear 210 accordingly. In this example, since the side of the rigid internal gear 210 is connected to the side of the device housing 2 and the second end plate 4 that are the fixed side, the side of the other first end plate 3 is decelerated and rotated. The rotation of the first end plate 3 is transmitted to the load side.

As described above, in the sealed wave gear device 1 of this example, the cylindrical device housing 2 and the first and second end plates located at the open ends of both sides of the device housing 2,
A configuration in which a closed space 13 is defined by the hollow input shaft 5 and first to fourth sealing means (8, 9, 11, 12) for sealing between them, and a wave gear mechanism 20 is incorporated therein. Has been adopted. Therefore, the wave gear mechanism 2
The lubricating oil for lubricating each part of 0 does not leak outside. Further, since only the device housing 2, the first and second end plates, and the input shaft 5 are exposed to the outside, only the exposed surface of these should be subjected to the rust prevention treatment. Therefore, the sealed wave gear device 1 of this example is suitable for being incorporated as a speed reduction mechanism of a drive mechanism used in a place where it is necessary to completely prevent the scattering of lubricating oil, the occurrence of rust, etc., such as in a clean room. ing.

Further, since the wave gear mechanism 20 of the present example is a flat type having a simple structure and a short length in the direction of the axis 1a, the entire apparatus can be made flat.

Further, since the hollow input shaft 5 is adopted, wiring and other members can be arranged by utilizing this hollow portion, which is convenient.

Although the cross roller bearing 30 is used in this example, a ball bearing can be used instead. Further, in this example, the second end plate 4 and the device housing 2 are configured as separate members, and these are fastened by the fastening bolts 40. Alternatively, the second end plate 4 and the device housing 2 may be integrally formed. In the present specification, for convenience of description, these members are described separately, but it is intended to naturally include the case where these members are manufactured as one body.
Furthermore, although the above example uses a hollow input shaft,
Of course, a normal non-hollow input shaft may be used.

[0029]

As described above, in the sealed wave gear device of the present invention, the cylindrical device housing, the first and second end plates arranged at both ends thereof, the input shaft,
A sealed space is defined by the first to fourth sealing means for sealing the space between them, and a wave gear mechanism is incorporated therein. Therefore, according to the present invention, it is suitable to be incorporated as a speed reducer in a drive mechanism used in a clean room or the like.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view showing a cross-sectional structure of a portion of a hermetically-sealed wave gear device that is an embodiment of the present invention, taken along the device axis.

[Explanation of symbols]

 1 Sealed Wave Gear Device 1a Device Axis 2 Device Housing 3 First End Plate 4 Second End Plate 5 Hollow Input Shaft 6, 7 Ball Bearing 8 Oil Seal 9 Oil Seal 11 Magnetic Seal 12 O-ring 13 Sealed Space 20 Wave Gear mechanism 210 Rigid internal gear 220 Flexible external gear 230 Wave generator 30 Cross roller bearing

Claims (6)

[Claims] 1. A cylindrical device housing, a first end plate located at a first open end on one side of the device housing, and a second open end on the other side of the device housing. A second end plate disposed on the inner side of the device housing, an input shaft coaxially disposed inside the device housing, and having both ends rotatably supported by the first and second end plates, respectively. First sealing means for sealing between the open end of the first end plate and the first end plate, second sealing means for sealing between the second open end and the second end plate, and the first end plate Third sealing means for sealing between the input shafts, fourth sealing means for sealing between the second end plate and the input shafts, the device housing, the first and second end plates And in a closed space defined by the first to fourth sealing means And a wave gear mechanism incorporated in the sealed wave gear device. 2. The wave gear mechanism according to claim 1, wherein the wave gear mechanism has a cylindrical body portion, external teeth formed on an outer peripheral surface of an open end of the body portion on the side of the first end plate, and a body portion of the body portion. A top-hat type flexibility including an annular diaphragm continuous from the opening end on the side of the second end plate toward the outer side in the radial direction and a thick annular boss continuous to the outer peripheral edge of the diaphragm. An external gear, an annular rigid internal gear that is arranged on the outer periphery of the external tooth and has internal teeth that can mesh with the external tooth on the inner peripheral surface, and a cylindrical body in which the external tooth is formed. And a wave generator that is arranged inside the portion to flex the cylindrical body in the radial direction to partially mesh the outer teeth with the inner teeth and move the meshing position in the circumferential direction. And the input shaft is fixed to the wave generator. Hermetic wave gear device characterized in that it extends through the wave generator with. 3. The flexible external gear according to claim 2, further comprising a bearing arranged on an outer periphery of a cylindrical body portion of the flexible external gear, the outer ring of the bearing including the device housing, the annular boss and the second ring. Of the above, the inner ring has the rigid internal gear and a bearing fixed to the first end plate. 4. The flexible external tooth according to claim 3, wherein the bearing is a cross roller bearing, and the flexible external tooth is provided between the second end plate and an annular step surface formed on an inner peripheral surface of the apparatus housing. These four members are fastened together with the annular boss of the gear and the outer ring of the cross roller belling sandwiched, and between the annular end surface of the inner ring of the cross roller bearing and the inner annular end surface of the first end plate. A hermetically-sealed wave gear device, wherein these three members are fastened in a state where the rigid internal gear is sandwiched between the three members. 5. The hermetic wave gear device according to claim 4, wherein the first sealing means is a magnetic seal. 6. The input shaft according to any one of claims 1 to 5, wherein the input shaft is a hollow input shaft, and both ends thereof extend through the first and second end plates, respectively. The characteristic wave gear device.